The invention relates generally to the field of aquaculture and, more particularly, to a system and method for producing aquatic species for consumer consumption. Although the invention relates to a method and system for producing many aquatic specie, the preferred embodiments disclose a method and system for producing shrimp.
While seafood has always been a staple in the diets of many people in the United States and elsewhere, it wasn""t until the 1980s that a significant increase in seafood consumption occurred. The consumption was largely the result of an increased awareness of the medical evidence that supported the health benefits and longevity accrued from a seafood diet. As a result, seafood distributors provided a greater abundance and selection of seafood products that further increased consumption. This increased domestic demand coupled with increased international demand by an expanding population led to more efficient methods for harvesting naturally occurring fish stocks from the oceans of the world. The increasingly efficient methods resulted in rapid depletion of these native fish stocks, requiring government intervention to impose restrictions on the size of the total harvest to preserve populations of certain native species. The smaller harvests resulted in increasing the price of seafood products, which helped stimulate the search for methods of growing fish stocks in a controlled artificial environment. The production of catfish in catfish farms is a dominant example of the growing, large-scale aquaculture industry. Other species produced by the aquaculture industry include crayfish, oysters, shrimp, Tilapia and Striped Bass.
The United States consumes about one billion of the approximately seven billion pounds of shrimp that are consumed annually by the world population. While seventy-five percent of this annual harvest is provided by ocean trawling, aquaculture in the form of shrimp farms provide the other twenty five percent. However, ocean trawling suffers from a limited season, a declining catch rate and environmental concerns. Shrimp farms may be categorized as open systems and closed systems.
Open system shrimp farms are generally open to the environment, such as open-air ponds constructed near oceans to contain and grow shrimp. These open shrimp farms suffer from vagaries of predators, the weather, diseases and environmental pollution. Saltwater from the ocean must be continually circulated through the ponds and back to the ocean to maintain adequate water chemistry for the shrimp to grow. The shrimp farmers must supply daily additions of dry food pellets to the shrimp as they grow.
Closed shrimp farms are generally self-contained aquaculture systems. While figs closed shrimp farms have greater control over the artificial environment contained therein, they have not been entirely satisfactory because of limited production rates, water filtration and treatment problems, and manufactured feed. Although some of these shortcomings can be overcome by increased capital expenditures, such as for water treatment facilities, the increased capital, labor and energy costs may be prohibitive.
It is desirable, therefore, to have a method and system for producing aquatic species, and particularly shrimp, that are not limited by a season, declining catch rate, environmental concerns, predators, weather, diseases, low production rates, water treatment problems, or manufactured feed. The system and method should not be limited to a specific location for access to a shipping facility or proximity to the ocean.
The present invention provides a closed aquaculture system and method for producing aquatic specie and other aquatic species that is not limited by the seasons of the year, is not limited by a declining catch rate, does not exhibit environmental concerns and is not affected by predators, weather, or diseases. The present invention provides high production rates, does not exhibit water treatment or manufactured feed problems, and is not limited to a specific location for access to a shipping facility or proximity to the ocean. Use of automation results in reduced labor costs and greater system density.
Unlike existing systems and methods, the present invention replicates a natural biological cycle by combining live algae, live artemia and live aquatic specie in a controlled environment. This combination of algae, artemia and aquatic specie stabilizes key system parameters. In addition, the system can achieve higher algae, artemia and aquatic specie density than existing systems by using automation to continually monitor and modify the saltwater environment.
A method having features of the present invention comprises a method for producing adult aquatic specie in an aquaculture system that comprises growing algae within an algae subsystem containing saltwater illuminated by a light source, flowing the algae from the algae subsystem into an artemia subsystem and an aquatic specie subsystem, both containing saltwater, consuming the algae and producing artemia by adult artemia within the artemia subsystem, passing the artemia from the artemia subsystem to the aquatic specie subsystem, consuming algae and the artemia by an immature aquatic specie for producing an adult aquatic specie within the aquatic specie subsystem, and harvesting the adult aquatic specie. The method may further comprise filtering a waste outflow from the aquatic specie subsystem by a filtration subsystem for providing a saltwater return to the algae subsystem, the artemia subsystem, and the aquatic specie subsystem. The method may further comprise controlling the aquaculture system with a data acquisition and control subsystem. The method may further comprise replenishing saltwater lost in the aquaculture system due to evaporation and leakage.
The step of growing algae within an algae subsystem may comprise seeding a selected strain of algae into the algae subsystem containing saltwater, illuminating the algae subsystem with light for proper algae growth, maintaining a temperature of the algae and saltwater by a heater means, measuring pH, algae density, temperature, light output, dissolved oxygen and nitrates, and controlling CO2 inflow, saltwater replenishment inflow, saltwater return inflow from a filtration subsystem, and algae outflow to the artemia subsystem. The selected strain of algae may be selected from the group consisting of isochrysis galbana, skeletonema, thalassiosira, phaeodactylum, chaetoceros, cylindrotheca, tetraselmis and spirulina. The temperature value may be maintained within the range of from 27xc2x0 C. to 32xc2x0 C. Controlling a CO2 inflow value may maintain the pH value within a range of from 7.5 to 8.5. The saltwater return inflow value may be selected to maintain an algae density value within a range of from 1 to 10 million cells per milliliter. The saltwater replenishment inflow salinity value may be maintained within a range of from 30 to 35 parts per thousand.
The step of consuming algae and producing artemia by adult artemia within the artemia subsystem may comprise adding artemia to the artemia subsystem containing saltwater for consuming algae and producing artemia, maintaining a temperature of the artemia, algae and saltwater by a heater means, measuring waste, algae density, artemia density, temperature, pH, ammonia, and dissolved oxygen, and controlling oxygen inflow, saltwater return inflow from a filtration subsystem, saltwater replenishment inflow, and artemia outflow to the aquatic specie subsystem. The temperature value may be maintained within the range of from 27xc2x0 C. to 32xc2x0 C. The controlling an oxygen inflow value may maintain the dissolved oxygen value within a range of from 4.5 parts per million to 9.0 parts per million. The controlling a saltwater return inflow value may maintain an artemia outflow value to the aquatic specie subsystem to adequately remove waste from the artemia subsystem and provide sufficient artemia to the aquatic specie subsystem for food. The saltwater replenishment inflow salinity value may be maintained within a range of from 30 to 35 parts per thousand. The preferred artemia specie originate from the Great Salt Lake in Utah, USA. The step of passing the artemia from the artemia subsystem to an aquatic specie subsystem may comprise filtering the artemia outflow from the artemia subsystem through a 400 micron screen to prevent adult artemia from leaving the artemia subsystem and allowing artemia waste and smaller artemia to pass to the aquatic specie subsystem.
The step of consuming algae and the artemia by an immature aquatic specie may comprise placing the immature aquatic specie in the aquatic specie subsystem for consuming algae and artemia for producing adult aquatic specie, maintaining a temperature of the aquatic specie, algae, artemia and saltwater by a heater means, measuring volume, waste, algae density, artemia density, aquatic specie size, aquatic specie density, temperature, pH, ammonia, and dissolved oxygen, and controlling oxygen inflow, saltwater return inflow from a filtration subsystem, saltwater replenishment inflow, nauplii inflow from the artemia subsystem, and waste outflow to the filtration subsystem. The step of controlling the waste outflow to the filtration subsystem may comprise filtering the waste outflow from the aquatic specie subsystem through a graded screen to prevent aquatic specie and artemia from leaving the aquatic specie subsystem and allowing waste products to pass to the filtration subsystem. The graded filter screen may comprise a 400 micron bottom section, an 800 micron lower middle section, a 2000 micron upper middle section, and a 5000 micron top section for enabling disposal of increased waste products from increasing size aquatic specie as the effective volume of the aquatic subsystem is increased by increasing a saltwater level to accommodate the larger specie size. The temperature value may maintained within the range of from 27xc2x0 C. to 32xc2x0 C. The controlling an oxygen inflow value may maintain the dissolved oxygen value within a range of from 4.5 parts per million to 9.0 parts per million. The controlling a saltwater return inflow value may maintain a waste outflow value to the filtration subsystem by controlling volume to adequately remove waste from the aquatic specie subsystem. The saltwater replenishment inflow salinity value may be maintained within a range of from 30 to 35 parts per thousand. The preferred aquatic specie may be selected from the group consisting of litopenaeus vannamei, monodon, indicus, stylirostis, chinensis, japonicus, and merguiensis. The optimum waste outflow rate from the aquatic specie subsystem may be selected to remove waste products from an aquatic specie density of from 0.25 to 0.5 pounds per gallon of saltwater.
The step of filtering a waste outflow from the aquatic specie subsystem may comprise a filtration subsystem for pumping the waste flow and filtering the waste flow through a mechanical filter, and a biofilter for providing a saltwater return. The step of controlling the aquaculture system may comprise connecting measurements from the algae subsystem, artemia subsystem and aquatic specie subsystem to an input multiplexer, connecting an output from the input multiplexer to an input of a microprocessor, connecting an output of the microprocessor to a controller output, connecting an output from the output controller to controls for the algae subsystem, the artemia subsystem, the aquatic specie subsystem, and the filtration subsystem, and connecting the microprocessor to a video monitor and keyboard for providing a user interface. The aquaculture system may comprise a closed recirculating system. The harvested adult aquatic specie may be shrimp.
In another embodiment of the present invention, a method for producing adult aquatic specie in an aquaculture system comprises growing algae in saltwater, feeding the algae to artemia in saltwater, producing artemia by the artemia in saltwater, feeding the algae and the artemia to an immature aquatic specie in saltwater to produce adult aquatic specie, and harvesting the adult aquatic specie from the saltwater when mature. The step of growing algae may comprise illuminating the algae in the saltwater by a light source, controlling a temperature of the algae in the saltwater by a heat source, regulating a CO2 inflow to control pH of the saltwater, replenishing saltwater lost due to evaporation and leakage, regulating a saltwater return inflow for controlling algae outflow, and measuring pH, algae density, temperature, light output, dissolved oxygen and micronutrients. The step of feeding the algae to artemia in saltwater may comprise providing an inflow of algae and saltwater into the artemia in saltwater, controlling a temperature of the algae and artemia in saltwater by a heat source, regulating an oxygen inflow to control dissolved oxygen, regulating a saltwater return inflow for controlling artemia, algae, waste and saltwater outflow, and measuring pH, algae density, temperature, ammonia, dissolved oxygen, waste, and artemia density. The step of producing artemia by the artemia in saltwater may comprise consuming algae by the artemia to generate artemia filtering the algae, artemia, waste and saltwater through a screen that allows the algae, smaller artemia, waste and saltwater to pass as an outflow while restraining the larger artemia. The step of feeding the algae and the artemia to an immature aquatic specie in saltwater to produce adult aquatic specie may comprise providing an inflow of algae, artemia, waste and saltwater to the immature aquatic specie in saltwater, controlling a temperature of the algae, artemia, waste and saltwater by a heat source, regulating an oxygen inflow to control dissolved oxygen, regulating a saltwater return inflow for controlling artemia, algae, waste and saltwater outflow, measuring aquatic specie density, aquatic specie size, pH, algae density, temperature, ammonia, dissolved oxygen, waste, volume and artemia density, consuming artemia by the immature aquatic specie to produce adult aquatic specie, and filtering the algae, aquatic specie, artemia, waste and saltwater through a graded screen that allows the algae, smaller artemia, waste and saltwater to pass as an outflow to a filtration means while restraining the aquatic specie.
In yet another embodiment of the present invention, an aquaculture system for producing adult aquatic specie comprises an algae subsystem containing saltwater illuminated by a light source for growing algae, means for flowing the algae from the algae subsystem into an artemia subsystem and an aquatic specie subsystem, both containing saltwater, the artemia subsystem containing adult artemia for consuming the algae and producing artemia, means for passing the artemia from the artemia subsystem to the aquatic specie subsystem, the aquatic specie subsystem containing an immature aquatic specie for consuming the algae and the artemia for producing an adult aquatic specie, and means for harvesting the adult aquatic specie. The system may further comprise a filtration subsystem for filtering a waste outflow from the aquatic specie subsystem and for providing a saltwater return to the algae subsystem, the artemia subsystem, and the aquatic specie subsystem. The system may further comprise a data acquisition and control subsystem for controlling the aquaculture system. The system may further comprise means for replenishing saltwater lost in the aquaculture system due to evaporation and leakage. The algae subsystem containing saltwater illuminated by a light source for growing algae may further comprise a heater for controlling a temperature of the algae subsystem, a CO2 inflow for controlling pH of the algae subsystem, a saltwater replenishment inflow for replacing saltwater lost to evaporation and leakage, a saltwater return inflow from a filtration subsystem, an algae outflow to the artemia subsystem, and measurement means for measuring pH, algae density, temperature, light output, dissolved oxygen, and micronutrients of the algae subsystem. The artemia subsystem containing adult artemia for consuming the algae and producing artemia may further comprise a heater for controlling temperature of the artemia subsystem, an oxygen inflow for controlling dissolved oxygen of the artemia subsystem, a saltwater replenishment inflow for replacing saltwater lost to evaporation and leakage, a saltwater return inflow from a filtration subsystem, a filter screen for separating the smaller artemia and waste from the adult artemia, an artemia outflow to the aquatic specie subsystem, and measurement means for measuring pH, algae density, temperature, ammonia, dissolved oxygen, waste, and artemia density of the algae subsystem. The aquatic specie subsystem containing an immature aquatic specie for consuming the algae and the artemia for producing an adult aquatic specie may further comprise a heater for controlling temperature of the aquatic specie subsystem, an oxygen inflow for controlling dissolved oxygen of the aquatic specie subsystem, a saltwater replenishment inflow for replacing saltwater lost to evaporation and leakage, a saltwater return inflow from a filtration subsystem, a graded filter screen for separating the aquatic specie from the waste algae and smaller artemia, a waste outflow to the filtration subsystem, and measurement means for measuring aquatic specie density, aquatic specie size, pH, algae density, temperature, ammonia, dissolved oxygen, waste, and volume of the algae subsystem. The graded filter screen may be selected from the group consisting of a planar filter screen and a cylindrical filter screen. The filtration subsystem may comprise a waste inflow from the aquatic specie subsystem connected to an inlet of a pump, an outlet of the pump connected to an input of a mechanical filter, an output of the mechanical filter connected to an input of a biofilter, and an output of the biofilter connected to saltwater return inflows of the algae subsystem, the artemia subsystem, and the aquatic specie subsystem. The data acquisition and control subsystem for controlling the aquaculture system may comprise an input multiplexer for accepting measurement inputs from the algae subsystem, the artemia subsystem and the aquatic specie subsystem, a microprocessor connected to an output of the input multiplexer, a monitor and keyboard user interface, and an input to an output controller, and control outputs of the output controller connected to the algae subsystem, the artemia subsystem, the aquatic specie subsystem, and the filtration subsystem. The measurement inputs may comprise pH, algae density, temperature, light output, dissolved oxygen and micronutrients from the algae subsystem, pH, algae density, temperature, ammonia, dissolved oxygen, waste, and artemia density from the artemia subsystem, and aquatic specie density, aquatic specie size, pH, algae density, temperature, ammonia, dissolved oxygen, waste, volume, and artemia density from the aquatic specie subsystem. The control outputs may comprise heater control, CO2 inflow, saltwater replenishment inflow, algae outflow, saltwater return inflow, and algae tank flow valves to the algae subsystem, heater control, oxygen inflow, artemia outflow, saltwater return inflow, algae inflow, and saltwater replenishment inflow to the artemia subsystem, heater control, oxygen inflow, waste outflow, saltwater return inflow, inflow, and saltwater return inflow to the aquatic specie subsystem, and pump speed control to the filtration subsystem.